Wednesday, November 18, 2009

What counts as auditory cortex?

I'm working on revisions of an fMRI paper that investigates the hierarchical organization of auditory cortex. Not surprisingly, the STS has figured into our findings. One reviewer raised the question of whether the STS is auditory cortex. This is a legit question and one that is not easy to answer.

The reviewer adopted a conservative definition of auditory cortex (conservative on his/her own admission): auditory cortex is cortex that receives projections from the medial geniculuate complex. I kind of like this definition because if we apply it to vision (using LGN projections of course), visual cortex = V1 (and maybe MT). THAT should slow down those greedy cortex grabbers! :-)

But surely this is too conservative. No one would claim that V2 isn't part of visual cortex just because it doesn't receive thalamic projections. So if vision people can claim territory beyond LGN projection fields, we should too.

But then where do we draw the line between auditory cortex and the rest of cortex? Do we base it on cytoarchitectonics? Do we include any auditory-responsive field as auditory cortex (which would include frontal areas!)? Is the notion of unimodal sensory cortex even meaningful?

What do you think?

Friday, November 13, 2009

Postdoctoral positions - Northwestern, Communication Sciences

The Department of Communication Sciences and Disorders at Northwestern University is pleased to announce the availability of PhD and postdoctoral fellow positions, funded by an NIH translational research training grant. The goal of the grant is to train young scientists in translational research in communication sciences and disorders, bridging basic and clinical research. Special emphasis is placed on translational projects related to sensory reception, motor control, and language processing. Postdoctoral candidates must hold a PhD in Communication Sciences and Disorders, Cognitive Science, Linguistics, Neuroscience, or a related field.

Trainees will receive funding for two years on this project. Additional funding is available for funding beyond the two years of this project. Interested candidates should send a cover letter stating your research interests and career goals, CV, and two letters of recommendation to Chuck Larson, Chair, Communication Sciences and Disorders, Northwestern University, 2240 Campus Dr., Evanston, IL 60208.

Applications will be reviewed quarterly, but it is anticipated that most positions will be filled at the beginning of the academic year in September.

Wednesday, November 11, 2009

Tenure-track or tenured professor Department of Communication Sciences and Disorders Emerson College, Boston, Massachusetts

The Department of Communication Sciences and Disorders at Emerson College
seeks to hire a tenure-track or tenured faculty member with primary expertise in the area of Speech-Language Pathology or a related field. Required qualifications are 1) a completed doctorate in Speech and Hearing Science, Communication Disorders, or a related discipline, 2) a record of excellence in teaching, and 3) an established record of research in Communication Sciences and Disorders. The successful applicant will be expected to publish research in her/his area of expertise, teach undergraduate and/or graduate courses, advise students, and participate in related academic service and scholarly activities. Appointment begins September 1, 2010.

Review of applications will begin January 11, 2010 and continue until the position is filled. Applicants should submit a letter of application (including a description ofresearch focus and teaching experience), a curriculum vita, and three letters of support to: CD Search Committee, Communication Sciences and Disorders, 120 Boylston Ave, Boston, MA 02116. Inquiries should be directed to Daniel Kempler, Department Chair, Daniel_Kempler@emerson.edu, 617-824-8302.

Emerson College values campus multiculturalism as demonstrated by the
diversity of its faculty, staff, student body, and constantly evolving curriculum. The successful candidate must have the ability to work effectively with faculty, students, and staff from diverse backgrounds. Members of historically underrepresented groups are encouraged to apply. Emerson College is an Equal Opportunity Employer that encourages diversity in its workplace.

Emerson College is the nation’s only four-year institution dedicated exclusively to majors in communication and the arts. The program in Communication Sciences & Disorders is one of the oldest and most respected in the country, and is highly ranked among the most competitive graduate programs in communication disorders in the US. The department offers state-of-the-art, handicap accessible, on-campus clinical facilities easily reached by public transportation. Emerson College is located in the center of Boston, surrounded by major healthcare and research centers, which provide a wide range of clinical and research opportunities for faculty and students. The College enrolls approximately 3,000 full-time undergraduates and nearly 1,000 full and part-time graduate students in its School of the Arts and School of Communication.

Tuesday, November 10, 2009

Cognitive Neuroscience Assistant or Associate Professor (tenure-track) - University of Washington Institute for Learning & Brain Sciences

The University of Washington’s Institute for Learning & Brain Sciences (I-LABS), an interdisciplinary brain research center, has a tenure-track faculty opening for an Assistant/Associate Professor in Cognitive Neuroscience with a focus on Language. Departmental affiliation can be in Psychology, Speech & Hearing Sciences, Linguistics, or Biology, depending on the applicant’s background and training. Ph.D. required. Appointment at the Associate Professor level will be considered for candidates who have an outstanding research record. I-LABS’ faculty study life-long learning and specialize in human cognitive development and learning. We have a growing developmental group at the Institute. The Institute will open its own MEG-Brain Imaging Center in April 2010. The successful candidate will be one who brings expertise in human cognitive neuroscience with a focus in the domain of language, development, and/or research using MEG/ERP. Faculty responsibilities will begin September 16, 2010.

Applicants should send a statement of teaching and research interests, curriculum vita, up to 5 publication reprints, and three letters of recommendation to:

Patricia Kuhl, Co-Director, Institute for Learning & Brain Sciences, Mailstop 357988, University of Washington, Seattle, WA 98195; e-mail: pkkuhl@u.washington.edu. Review of applications will begin in January 15, 2010, will continue until the position is filled.

The University of Washington is an affirmative action, equal opportunity employer, and is building a culturally diverse faculty and staff and strongly encourages applications from women, minorities, individuals with disabilities and covered veterans. UW faculty engages in teaching, research and service. The University of Washington, a recipient of the 2006 Alfred P Sloan award for Faculty Career Flexibility, is committed to supporting the work-life balance of its faculty.

Friday, November 6, 2009

The Pinker Panther Strikes Again - Recording from Broca’s Area

In a recent issue of Science (Vol 326, 445-449), Sahin, Pinker, Cash, Schomer, and Halgren summarize their findings from direct recordings from Broca’s region in patients undergoing presurgical epilepsy evaluation.

In an earlier, 2006, paper in Cortex, Sahin, Pinker, and Halgren reported fMRI data in participants doing one of the garden-variety past-tense tasks used often by Steve Pinker and his students and colleagues (the style of the experiment is something like this “visual cue: Yesterday I was in the park and ___. Target: to walk” -> participant produces “walked”). This 2009 paper is the fancier, intra-cranial recording companion piece (ICE, in their terminology, intracranial electrophysiology :-).

The piece represents something like the ‘harmonic convergence’ between the current enthusiasm for intracranial electrophysiological data (is anyone not doing this?), the long (historical) reach of Pinker’s past-tense-as-psycholinguistic-drosophila philosophy (yes, I remember having to read Pinker and Prince in grad school; and Greg even worked on some of this stuff!), and the growing interest in better cognitive neuroscience of language models.

Peter Hagoort and Pim Levelt provide a perspective in the same issue of Science (Vol 326, 372-373), largely because these data are directly linked to the Levelt production model. The numbers reported by Sahin et al. match nicely with Levelt’s production model (see, e.g. Indefrey & Levelt, 2004, Cognition) -- so the Max-Planck guys are certainly happy.

The centerpiece of the study -- recordings from three patients who also underwent fMRI scanning prior to electrode implantation -- concerns data from electrodes in Broca’s region, perhaps Brodmann’s area 45 (that point is not made with sufficient clarity). They identified in the electrode response three peaks, or rather a tri-phasic response. Across all three patients, there were peaks/valleys at ~200 ms, ~320 ms, and ~450 ms post-target onset. The first, 200 ms, peak was modulated by lexical manipulations (frequency), the second, 320 ms, peak by inflectional demands (grammatical manipulations), the third, 450 ms, peak by articulatory requirements. Based on these observations, they conclude (and this is the title of the article): “Sequential processing of lexical, grammatical, and phonological information within Broca’s area.”

The results are not particularly surprising. When presented with a word, it stands to reason that it has to be accessed/identified before it can be repeated … (Planning a word’s articulation before even seeing it would indeed be pretty novel.) Moreover, if any operation on the input representation is required prior to articulation, it is also not super-surprising that it would be temporally interposed between lexical access and articulatory planning/output generation. What would be the alternative? What is interesting in these data is that there is evidence for these stages in one very small region. Of course, many other regions will also play a role – here, by clinical necessity, only a small region can be investigated. What is not clear is whether the activation observed is functionally critical, i.e. whether the reported triphasic Broca’s region activity is necessary for the execution of these language tasks. If we want to conclude that Broca’s region provides the neuronal substrate for multiple different operations that participate causally in the execution of multiple language tasks – again, is there a credible alternative? – it would help to get a better sense of the role such localized frontal activation plays. In any case, the paper reflects the growing use of intra-cranial data in the study of language (see, e.g., the studies by Boatman, Crone, Knight, etc.)

Thursday, November 5, 2009

Why "where" cannot be a sensory processing stream

There is debate about the nature of the dorsal auditory processing stream. Some folks, Josef Rauschecker in particular, argue for a dorsal "where" stream, whereas others, Hickok & Poeppel and Warren et al., argue for a sensory-motor integration (sometimes called "how") stream. Here's why the "where" hypothesis can't, in principle, be right.

Spatial information associated with an auditory signal is a stimulus feature much like pitch. We don't talk about a "pitch stream" however. Why not? Because pitch (frequency) is just a cue for any number of processing goals. Pitch information can cue phonemic identity, speaker voice, auditory stream segregation ... even sensory-motor goals (humming back a tone). Spatial cues are no different in that they can cue explicit location judgments, auditory stream segregation, and any number of sensory-motor processes (head movements, saccades, locomotion toward or away from a source).

Processing streams, I'm suggesting, are defined by goals or tasks -- what the information is used for -- not by stimulus features. Sensory-motor integration for vocal tract actions defines a goal -- control of the vocal tract -- and therefore is a viable candidate for a processing stream. Identifying the meaning of an auditory object is also a goal and a good candidate for a processing stream. Stimulus features, like pitch or location are not goals, they are just cues that can be used within various task-driven processing streams.

Of course, this doesn't imply that there isn't a specialized location processing system in the brain that uses interaural time and level differences to compute spatial information. Almost for sure there is (my guess is that it's subcortical), just like there is a system that processes pitch using frequency information. But we shouldn't confuse a specialized feature processing system (area) with a cortical processing stream as the notion "stream" is typically used.

Which reminds me. It is probably time to redefine the notion of a processing "stream". In particular, I think the dorsal-ventral distinction is getting tired and has now outlived its usefulness. I'll expand in a later post...

References

Hickok, G., & Poeppel, D. (2000). Towards a functional neuroanatomy of speech perception Trends in Cognitive Sciences, 4 (4), 131-138 DOI: 10.1016/S1364-6613(00)01463-7

Hickok, G., & Poeppel, D. (2007). The cortical organization of speech processing Nature Reviews Neuroscience, 8 (5), 393-402 DOI: 10.1038/nrn2113

Rauschecker JP, & Scott SK (2009). Maps and streams in the auditory cortex: nonhuman primates illuminate human speech processing. Nature neuroscience, 12 (6), 718-24 PMID: 19471271

Warren JE, Wise RJ, & Warren JD (2005). Sounds do-able: auditory-motor transformations and the posterior temporal plane. Trends in neurosciences, 28 (12), 636-43 PMID: 16216346

Monday, November 2, 2009

TENURED SENIOR FACULTY POSITION AT BOSTON UNIVERSITY

The Department of Speech, Language and Hearing Sciences at Boston University invites applications for the position of Senior Faculty at the level of Associate/Full Professor. Candidates should have demonstrated a strong research background and a successful record of obtaining external support for research and training/mentoring activities. Qualifications include: (a) earned doctorate with a specialty in one of the communication sciences or disorders areas, (b) experience in teaching, research and mentoring, and (c) clinical certification is preferred, but not required. Areas of research expertise are open but we encourage candidates with a clear interest in interdisciplinary research collaboration. The Department is moving to a rotating Chair model with a limited appointment as Chair and all senior faculty will be eligible to serve in this administrative opportunity as appropriate to their overall career development. This is a full-time, tenure track position, with a 9-month appointment. Rank and salary will be commensurate with qualifications and level of experience.
Registered Email
s-kiran@mail.utexas.edu
Contact Name
Swathi Kiran
Contact Address
For questions regarding this position, please email
Swathi Kiran Ph.D CCC-SLP, Chair of the search committee
kirans@bu.edu or call 617-358-5478
Application packets should be directed to:


Speech, Language and Hearing Sciences Search Committee
Boston University
College of Health and Rehabilitation Sciences: Sargent College
635 Commonwealth Avenue
Boston, MA 02215
Contact Email
kirans@bu.edu
Contact Phone
617-358-5478
Contact Website
http://www.bu.edu/sargent/

Faculty Position in Developmental Disorders of Speech, Language and Learning, Northwestern University

The Roxelyn and Richard Pepper Department of Communication Sciences
and Disorders at Northwestern University is searching for a
tenure-track assistant professor to begin September 2010 who will lead
a translational research program in the developmental disorders of
speech and learning (e.g., apraxia, phonological disorders). An
exceptional candidate may be considered for an endowed junior chair
position. Clinical certification is not required. In addition to an
earned doctorate from relevant fields (e.g., psychology, learning
science, speech science, neurobiology, genetics, molecular and cell
biology, biomedical engineering), applicants must have demonstrated
potential to lead a high-impact, externally-funded research program.
Northwestern University is a founder and leader of the discipline of
Communication Sciences and Disorders with undergraduate, professional
(Audiology, Speech-Language Pathology, and Learning Disabilities), and
PhD training programs; innovative and interdisciplinary approaches to
teaching and research dominate the direction of the University.

Duties: Develop a fundable program of research, teach courses in
developmental speech sciences and disorders and related topics, direct
student research, and engage in service to the department, school, and
university.

Qualifications: An earned PhD, a record of peer-reviewed publications,
potential for obtaining external grant funding, and potential for
being an effective teacher. Clinical qualification is not required.

Salary: Internationally competitive, depending on qualifications and experience.

Application procedures: Candidates should send a CV, research and
teaching statements, reprints of published articles, and four letters
of reference to: Charles Larson, PhD, CSD Faculty Search Committee
Chair (2240 Campus Dr., Evanston, IL 60208).

The University: Northwestern University is one of the nation’s largest
private research universities. The main campus is located in Evanston
and the medical campus is located 12 miles south in Chicago. Both
campuses are located on the shore of Lake Michigan. There is
continuing expansion of University facilities and programs,
particularly in the sciences and medicine. Cultural, social, and
recreational activities abound on and near each campus. For more
information, please visit:
http://www.communication.northwestern.edu/departments/csd/.

Closing Date: Ongoing until position is filled. Review of
applications will begin December 15, 2009.

Northwestern University is an Affirmative Action, Equal Opportunity
Employer. Women and minorities are encouraged to apply. Hiring is
contingent on eligibility to work in the United States.

Search # 15116
Registered Email
j-booth@northwestern.edu
Contact Name
Charles Larson

Faculty Positions: University of Maryland

The Linguistics Department at the University of Maryland seeks outstanding applicants for two tenure-track positions in the cognitive science of language. The first position is an Assistant or Associate Professor position in computational psycholinguistics, with a focus on models of human language processing and/or language learning. The second position is a tenure-track Assistant Professor position in the cognitive neuroscience of language. Candidates for both positions should contribute to a vibrant interdisciplinary language and cognitive science community that spans Linguistics and many other departments, programs, and institutes (e.g., Neuroscience and Cognitive Science, Electrical Engineering, Computer Science, Psychology, Hearing and Speech, Second Language Acquisition, Human Development, Center for Advanced Study of Language), and should contribute to the university's NSF-IGERT graduate training program in Biological and Computational Foundations of Language Diversity. The cognitive neuroscientist should ideally be able to take advantage of the university's multi-modal neuroimaging resources, which include ERP and MEG facilities and a new NSF-sponsored 3T fMRI facility (opening in 2010). Candidates for both positions should demonstrate the ability to lead an innovative and collaborative program of research and teaching that integrates computational and experimental approaches with linguistics and should have a Ph.D. in Linguistics or another Cognitive Science-related field.

For best consideration, applicants should submit a letter of application, including a research statement, a CV, and representative samples of scholarship by December 1, 2009 (by email if possible). Three letters of recommendation should be submitted separately (also by email if possible). Please indicate whether you plan to attend the LSA meeting in Baltimore. The position is open until filled.

Applications should be submitted to: linguistics_search@umd.edu or to: Search Committee, Linguistics Department, 1401 Marie Mount Hall, University of Maryland, College Park, MD 20742, USA.

The University of Maryland is an Equal Opportunity, Affirmative Action employer. Applications from women and minority candidates are especially encouraged
Registered Email
idsardi@umd.edu
Contact Name
William Idsardi
Contact Address
Contact Email
linguistics_search@umd.edu
Contact Phone
301-405-8376